Double ferrule SC connector and adapter

ABSTRACT

A fiber optic connector has two ferrules contained within a single connector housing with the ferrules positioned in parallel, spaced-apart alignment. The connector includes a first mating fastener exposed on exterior sides of the connector housing. A fiber optic adapter has an open end to slidably receive the connector housing. The adapter includes two parallel sleeves contained within the adapter housing and aligned with the ferrules of the connector. The adapter includes a second mating fastener exposed to an interior of the adapter housing to releasably mate with the first mating fastener when the connector housing is in the full insert position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.08/720,764, filed Oct. 3, 1996 now U.S. Pat. No. 5,692,080.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to fiber optic connectors and adapters forcoaxially connecting fiber optic cables. More particularly, thisinvention pertains to an adapter to accept two ferrules to double thedensity of connections.

2. Description of the Prior Art

Fiber optics have revolutionized telecommunications throughout theworld. With the increased use of fiber optics, it is increasinglyimportant to be able to connect and disconnect fiber optic cables fromvarious sources. Two fiber optic cables can be optically coupled so thatthey are in communication with one another by using well-known SCconnectors and an SC adapter thereby putting each fiber optic cable incommunication with the other. The SC connectors are placed on the end ofeach cable and then plugged into the adapter. The adapter has twoopenings, each one designed to receive a connector.

An example of an SC adapter and connector are shown in commonly assignedU.S. Pat. No. 5,317,663 to Beard, et al. dated May 31, 1994. In the '663patent, the adapter is shown in FIG. 4 and the connector is shown inFIG. 3. The disclosure of the '663 patent is incorporated herein byreference.

Fiber optic connectors are commonly organized such that two adjacentconnectors and adapters perform transmit and receive functions,respectively, in the fiber optic circuit. Historically, such separatetransmit and receive connectors and adapters would be positioned inclose proximity. The prior art has developed so-called duplex adapterswhere transmit and receive connectors are joined. An example of such isa Single Mode Duplex SC and Multi Mode Duplex SC of Amp Corporation.Such prior art duplex SC connectors require a substantially increasedvolume over single SC connectors such as that shown in U.S. Pat. No.5,317,663. It is desirable to increase the density of connectors in atelecommunications plant. It is the object of the present invention toprovide a dual SC connector and adapter requiring no greater area thanthat required by the single SC connector and adapter shown in U.S. Pat.No. 5,317,663.

SUMMARY OF THE INVENTION

According to a preferred embodiment of the present invention, an opticalfiber connector assembly includes a fiber optic connector and a fiberoptic adapter. The connector includes a connector housing having aleading end. A first and second ferrule are contained within theconnector housing. The first and second ferrules are positioned inparallel, spaced-apart alignment at the leading end. Also, the ferruleshave exposed ends at the leading end of the connector housing. Theconnector housing includes a first mating fastener exposed on exteriorsides of the connector housing. The adapter includes an adapter housinghaving an open end sized to slidably receive the leading end of theconnector housing. The connector housing moves within the adapterhousing to a full insert position. The adapter housing contains firstand second parallel sleeves which are positioned to slidably receiverespective ones of the first and second ferrules as the connectorhousing is moved to the full insert position. The adapter housingincludes a second mating fastener exposed to an interior of the adapterhousing to releasably mate with the first mating fastener when theconnector housing is in the full insert position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an adapter according to the present inventioncoupled to a connector according to the present invention to form aconnector/adapter assembly according to the present invention.

FIG. 2 is a view taken along line 2—2 of FIG. 1;

FIG. 3 is a cross-sectional longitudinal view of the assembly of FIG. 1rotated 90° from the view of FIG. 2,

FIG. 4 is a front, top, and side perspective view of a connectoraccording to the present invention;

FIG. 5 is the view of FIG. 4 with an outer housing of the connectorremoved to expose an interior housing;

FIG. 6 is a longitudinal cross-sectional view of the connector of FIG.4;

FIG. 7 is the view of FIG. 4 rotated 90°;

FIG. 8 is a perspective view of an adapter of the present invention;

FIG. 9 is a perspective view of a first mating half of a housing of theadapter shown in FIGS. 1-3; and

FIG. 10 is a perspective view of a second mating half of an adapterhousing containing a sleeve sub-assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference now to the several drawing figures in which identicalelements are numbered identically throughout, a description of thepreferred embodiment of the present invention will now be provided.

With initial reference to FIGS. 1-3, a fiber optic connector/adapterassembly 10 includes a fiber optic connector 12 and a fiber opticadapter 14. Single ferrule fiber optic connectors and adapters are shownin commonly assigned U.S. Pat. No. 5,317,663 incorporated herein byreference. Such adapters include openings for receiving two connectorsin order to optically couple the connectors. In FIGS. 1-3, only a singleconnector 12 is shown inserted into the adapter 14 for purposes ofclarity. It will be appreciated that, in use, two connectors 12 will becoupled to a single adapter 14 in order to optically couple the twoconnectors 12.

The connector 12 is separately shown in FIGS. 4-7. Shown best in FIGS. 4and 5, the connector 12 includes a connector housing 16 formed by anouter housing 18 slidably received over an inner housing 20. In FIG. 5,the outer housing 18 is not shown so that the inner housing 20 may beclearly illustrated. In FIG. 4, 6 and 7, the outer housing 18 is shownover the inner housing 20.

Two ferrules 22 are contained within the inner housing 20 with theferrules 22 mounted in parallel, spaced-apart alignment. Ends of theferrules 22 extend beyond a leading end 16a of the housing 16.

Each of the ferrules 22 is mounted in a hollow ferrule hub 24. The hubs24 and attached ferrules 22 are slidably moveable within the innerhousing 20 in a direction coaxial with the longitudinal axes of theferrules 22. Hubs 24 may be keyed to inner housing 20 to restrictrotation of hubs 24.

Springs 26 surround the hubs 24 with the springs 26 urging the ferrules22 outwardly from the leading end 16a. Each of the ferrules 22 andsprings 26 are independent such that each of the ferrules 22 isseparately urged outwardly from leading end 16a.

The inner housing 20 further includes a mandrel 28 onto which a fiberoptic cable (not shown) may be attached. The fiber optic cables are notshown in the figures, but such a cable would include a narrow or thinoptical fiber which would extend within the axial bore of the ferrules22. Such cables would also include sheathing to be secured to themandrels 28. A strain relief jacket 30 surrounds the mandrel 28 and issecured to the inner housing 20.

The inner housing 20 includes opposite side walls 32 (FIG. 5) having anexposed detent 34 with the two detents 34 positioned on opposite sidesof the inner housing 20. The outer housing 18 includes opposite sidewalls 35 (FIG. 4) having cutouts 36 such that the side walls 32 anddetents 34 are exposed through the side walls 35. Therefore, the detents34 are exposed on exterior sides of the connector housing 16. The outerhousing 18 further includes a guiding tab 38 and a knurled handle 40.The side walls 35 further include a ramp or cam surface 42 in the regionof the cutout 36 and positioned adjacent the detents 34.

The adapter 14 is shown in FIGS. 1-3. The adapter includes an adapterhousing 46 formed of identical mating halves 46a, 46b. A single adapterhousing mating half 46a is shown separately in FIG. 9. Half 46b isseparately shown in FIG. 10. The adapter housing 46 includes side walls60 opposing the outer side walls 32, 35 of the outer housing 18 andinner housing 20. Pins 47 are added to the half 46a aligned with a hole47a on half 46b so that halves 46a, 46b may be joined to form a completehousing 46. The pins 47 permit alignment so that a seam between halves46a, 46b may be ultrasonically welded.

The adapter 14 is symmetrical relative to a transverse axis X—X (FIG.3). For purposes of this description of the preferred embodiment, adescription of the side of adapter 14 to receive connector 12 (i.e., tothe right of axis X—X in FIG. 3) will be described. It will beappreciated that the opposite side of adapter 14 (i.e., to the left ofaxis X—X in FIG. 3) is identical in construction to receive a similarconnector 12.

The adapter housing 46 includes an open end 48 sized to slidably receivethe leading end 16a of the connector housing 16. Exterior surfaces ofthe outer connector housing 18 are complementarily shaped to theinterior surface of the adapter housing 46 so that housing 18 is inclose tolerance to housing 46 and is guided by housing 46 as housing 18is inserted. The connector housing 16 moves toward a full insertposition shown in FIGS. 1-3 along a path of travel parallel to theferrules 22. The housing 46 has a slot 37 to receive tab 38.

A sleeve subassembly 50 is contained within an interior of the adapterhousing 46. The sleeve subassembly 50 includes identical mating halves52 joined to define a flange 53. The flange 53 is received within amating groove 54 of the adapter housing 46. The subassembly matinghalves 52 define two parallel bores 56 formed therethrough aligned withthe ferrules 22. Two ferrule sleeves 58 are retained within the bores56. The sleeves 58 are positioned to slidably mate with the ferrules 22when the connector 12 is inserted into the adapter 14 to the full insertposition shown in FIGS. 1-3.

As shown in FIGS. 2 and 3, when a single connector 12 is inserted intothe adapter 14 to the full insert position, the terminal ends of theferrules 22 extend beyond the axis X—X. When a second connector isinserted into the opposite side of the adapter 14, the ferrules of thesecond connector will abut the ferrules 22 of the first connector 12.The springs 26 will permit the ferrules 22 to move away from axis X—Xand reach an equilibrium point such that opposing ferrules will be inface-to-face abutting engagement at a part line along axis X—X. Thesleeves 58 maintain the opposing ferrules in coaxial alignment such thatopposing ferrules are provided with their contained optical fibers beingoptically aligned and coupled.

The adapter housing side walls 60 are provided with cutouts 62.Contained within the cutouts 62 are cantilevered clips 64. Cantileveredclips 64 are positioned to be received within the detents 34 when theconnector 12 is inserted into the adapter 14 at the full insertposition. Further, the cam surface 42 of outer housing 18 opposes theclips 64 Accordingly, when the outer housing 18 is moved in a parting orseparating direction relative to the inner housing 20, the cam surface42 engages the clips 64 moving the clips 64 outwardly to free the clips64 from the detents 34 permitting removal of a connector 12 from theadapter 14 It will be noted that by providing the cutouts 62, the clips64 may expand at least partly into the side walls 60.

With respect to the structure shown in U.S. Pat. No. 5,317,663, theadapter of the prior art includes solid side walls. A sleeve subassemblyincludes clips contained completely within the interior of the adaptersuch that the clips remain completely within the interior of the adapteras the clips are deflected in response to a connector inserted into theadapter.

In the present invention, the clips 64 are moved to the exterior wallsof the adapter such that the clips 64 may partially deflect into theexterior walls 60 of the adapter 14 This arrangement greatly increasesthe available volume within the adapter 14 such that two ferrules 22 maybe inserted into the adapter 14 of the present invention while only asingle ferrule could be inserted into the adapter of the prior art shownin U.S. Pat. No. 5,317,663 thereby doubling the density. Accordingly,for an adapter 14 having identical external dimensions (i.e.,“footprint”) to that shown in U.S. Pat. No. 5,317,663, the presentinvention permits a doubling of the optical coupling within the adapter.The product of the '663 patent uses a standard 2.5 mm diameter ferrule.In the present invention, to achieve the same footprint either 1.25 mmor 2.5 mm diameter ferrules 22 can be used.

In addition to increasing the density of the optical coupling, tworelated fibers (i.e., namely transmit and receive fibers) can besimultaneously connected within a single adapter 14. This facilitatesthe connections made by a technician since only a single connection needbe made in order to couple related transmit and receive fibers whereas asingle SC adapter such as that shown in U.S. Pat. No. 5,317,663 requirestwo such connections per related transmit and receive fibers.

From the foregoing, it has been shown how the objects of the inventionhave been attained in a preferred manner Namely, with the same externalvolume as a prior art single SC adapter shown in U.S. Pat. No.5,317,663, applicant has modified the adapters 14 and connectors 12 topermit two fibers to be simultaneously connected in a single adapter 14having the same external volume of the prior art single adapter. Thisboth increases the functionality and density of fiber optic connectionsover the prior art.

While the invention has been disclosed in a preferred embodiment, itwill be appreciated that modifications and equivalents of the disclosedconcepts such as those which readily occur to one skilled in the artshall be included within the scope of the claims which are appendedhereto.

1. An optical fiber connector assembly comprising: a. a fiber opticconnector having: i. a connector housing having a leading end; ii. atleast a first ferrule and a second ferrule contained within saidconnector housing with; A. said first and second ferrules positioned inparallel, spaced-apart alignment at said leading end, and B. saidferrules having exposed ends at said leading end; iii. said connectorhousing including a first mating fastener exposed on exterior sides ofsaid connector housing, said first mating fastener including a clipreceiving detent formed on exposed external surfaces of said connectorhousing; b. a fiber optic adapter having: i. an adapter housing havingan open end sized to slidably receive said leading end of said connectorhousing with said connector housing moving toward a full insert positionin a path of travel parallel to said ferrules; ii. at least a first anda second parallel sleeves contained within said adapter housing andpositioned for said first and second sleeves to slidably receiverespective ones of said first and second ferrules as said connectorhousing is moved toward said full insert position; iii. a second matingfastener including a clip on said adapter housing and exposed to aninterior of said housing to releasably mate with said first matingfastener when said connector housing is moved to said full insertposition; and iv. walls of said adapter housing having recesses at leastpartially formed therethrough, said clips at least partially disposedwithin said recesses and said clips movable into said recesses as saidclips are deflected in response to insertion of said leading end of saidconnector housing into said adapter housing.
 2. An assembly according toclaim 1 wherein: said adapter housing includes substantially identicalfirst and second halves each having an individual one of said externalclips.
 3. An assembly according to claim 2 wherein: said sleeves aresupported in a sleeve sub-assembly having means for securing saidsub-assembly within said adapter housing as said first and second halvesare joined together.
 4. An assembly according to claim 3 wherein saidsub-assembly includes: a sleeve housing having first and second parallelbores formed therethrough; said first and second sleeves retained withinrespective ones of said bores; said sleeve housing having a flangereceived within a groove formed in said first and second halves.
 5. Anassembly according to claim 1 wherein: said first and second ferrulesare slidable independent of one another within said connector housing ina sliding path parallel to longitudinal axes of said ferrules.
 6. Anassembly according to claim 5 further comprising: first and secondspring means for separately urging said first and second ferrulesoutwardly from said leading end.
 7. An assembly according to claim 1wherein: said connector housing includes an internal housing slidablyreceived within an external housing; said first mating fastener disposedon said internal housing; said external housing having an opening formedtherethrough to expose said first mating fastener.
 8. An assemblyaccording to claim 7 wherein: said external housing includes releasemeans for releasing said first and second mating fasteners uponseparating, sliding movement of said external housing relative to saidinternal housing.
 9. A fiber optic connector for releasably couplingwith a fiber optic adapter where said adapter includes, a. an adapterhousing having an open and exposing an adapter interior; b. at least afirst and a second parallel sleeves contained within said adapterhousing and positioning with open ends of said first and second sleevesexposed to said open end of said adapter housing; and c. an adaptermating fastener including clips on said adapter housing and exposed tosaid adapter interior; said connector comprising: a. a connector housinghaving a leading end sized to be received with said adapter open end; b.at least a first ferrule and a second ferrule contained within saidconnector housing with; i. said first and second ferrules positioned inparallel, spaced-apart alignment at said leading end, and ii. saidferrules having exposed ends at said leading end and positioned to beslidably received in respective one of said first and second sleeves assaid connector housing is inserted into said adapter interior throughsaid adapter open end; b. said connector housing including a connectormating fastener exposed on exterior sides of said connector housing toreleasably mate either said adapter mating fastener as said connectorhousing is inserted into said adapter interior through said adapter openend; and c. said connector mating fastener including clip receivingdetents on exposed external surfaces of said connector housing andpositioned to mate with said clips when said connector housing isinserted into said adapter to a full insert position.
 10. A connectoraccording to claim 9 wherein: said first and second ferrules areslidable independent of one another within said adapter housing in asliding path parallel to longitudinal axes of said ferrules.
 11. Aconnector according to claim 10 further comprising: first and secondspring means for separately urging said first and second ferrulesoutwardly from said leading end.
 12. A connector according to claim 9wherein: said connector housing includes an external housing slidablyreceived within an external housing, said connector mating fastenerdisposed on said internal housing; said external housing having anopening formed therethrough to expose said first mating fastener.
 13. Aconnector according to claim 12 wherein: said external housing includesrelease means for releasing said first and second mating fasteners uponseparating, sliding movement of said external housing relative to saidinternal housing.
 14. An fiber optic adapter for releasably couplingwith a fiber optic connector where said connector includes: a. aconnector housing having a leading end; b. at least a first ferrule anda second ferrule contained within said connector housing with; i. saidfirst and second ferrules positioned in parallel, spaced-apart alignmentat said leading end, and ii. said ferrules having exposed ends at saidleading end; c. said connector housing including a first mating fastenerexposed on exterior sides of said connector housing, said first matingfastener including clip receiving detents formed on exposed externalsurfaces of said connector housing; said adapter comprising: a. anadapter housing having an open end sized to slidably receive saidleading end of said connector housing with said connector housing movingtoward a full insert position in a path of travel parallel to saidferrules; b. at least a first and a second parallel sleeves containedwithin said adapter housing and positioned for said first and secondsleeves to slidably receive respective ones of said first and secondferrules as said connector housing is moved toward said full insertposition; c. a second mating fastener exposed to an interior of saidadapter housing to releasably mate with said first mating fastener whensaid connector housing is moved to said full insert position; d. saidsecond mating fastener including clips on said adapter housingpositioned to mate with said detents as said connector housing isinserted into said open end of said adapter housing to a full insertposition; and e. walls of said adapter housing including recesses atleast partially formed therethrough sized to receive said clips as saidclips are deflected in response to insertion of said leading end of saidconnector housing into said adapter housing.
 15. An adapter according toclaim 14 wherein said adapter housing includes substantially identicalfirst and second halves each having an individual one of said externalclips.
 16. An adapter according to claim 15 wherein said sleeves aresupported in a sleeve sub-assembly having means for securing saidsub-assembly within said adapter housing as said first and second halvesare joined together.
 17. An adapter according to claim 16 wherein saidsub-assembly includes: a sleeve housing having first and second parallelbores formed therethrough; said first and second sleeves retained withinrespective ones of said bores; said sleeve housing having a flangereceived within a groove formed in said first and second halves.
 18. Anoptical fiber connector assembly comprising: a. a fiber optic connectorhaving a connector housing, the connector housing including a leadingend, and first and second ferrules adjacent to the leading end of theconnector housing; b. a fiber optic adapter having an adapter housing,the adapter housing having a central open end, and first and secondsleeves positioned to communicate with the open end;
 1. the first andsecond sleeves positioned parallel to one another;
 2. the first andsecond sleeves positioned and sized to receive respective ones of thefirst and second ferrules as the connector housing is fully insertedinto a full insert position; and
 3. the open end having an outerperimeter defining an SC footprint.
 19. The optical fiber connectorassembly of claim 18 further comprising a clip arrangement forreleasably mating the connector to the adapter.
 20. The optical fiberconnector assembly of claim 18 wherein the adapter housing includes anexterior flange, and further comprising an exterior clip on the adapterhousing, the clip spaced from the exterior flange.
 21. The optical fiberconnector assembly of claim 18 wherein the open end is a first open end,wherein the adapter housing includes a second open end opposite thefirst open end, wherein the second open end is sized for receiving asecond fiber optic connector including a second connector housing, thesecond connector housing including a leading end, and first and secondferrules adjacent to the leading end of the second connector housing ofthe second fiber optic connector.
 22. A fiber optic adapter for use witha single fiber optic connector having a connector housing including aleading end, and first and second ferrules adjacent to the leading end,the fiber optic adapter comprising: a. an adapter housing having acentral open end, and first and second sleeves positioned to communicatewith the open end;
 1. the first and second sleeves positioned parallelto one another;
 2. the first and second sleeves positioned and sized toreceive respective ones of the first and second ferrules as theconnector housing is fully inserted into a full insert position;
 3. theopen end having an outer perimeter defining an SC footprint; and b. aclip for releasably connecting to the connector housing.